The grain sizes of soft CH₃NH₃PbI₃ (MAPbI₃) thin films and the atomic contact strength at the MAPbI₃/P3CT-Na interface are manipulated by varying the drying time of the saturated MAPbI₃ precursor solutions, which influences the device performance and lifespan of the resultant inverted perovskite photovoltaic cells. The atomic-force microscopy images, cross-sectional scanning electron microscopy images, photoluminescence spectra and absorbance spectra show that the increased short-circuit current density (J_SC) and increased fill factor (FF) are mainly due to the formation of merged MAPbI₃ grains. Besides, the open-circuit voltage (V_OC) of the encapsulated photovoltaic cells largely increases from 1.01 V to 1.15 V, thereby increasing the power conversion efficiency from 17.89% to 19.55% after 30 days, which can be explained as due to the increased carrier density of the MAPbI₃ crystalline thin film. It is noted that the use of the optimized drying time during the spin coating process results in the formation of merged MAPbI₃ grains while keeping the contact quality at the MAPbI₃/P3CT-Na interface, which boosts the device performance and lifespan of the resultant perovskite photovoltaic cells.

中文翻译：

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干燥时间对合并和软 MAPbI3 晶粒形成及其光伏响应的影响

_{软 CH 3} NH ₃ PbI ₃ (MAPbI ₃ )薄膜的晶粒尺寸和 MAPbI ₃ /P3CT-Na 界面的原子接触强度通过改变饱和 MAPbI ₃前体溶液的干燥时间来控制，这会影响器件所得倒置钙钛矿光伏电池的性能和寿命。原子力显微镜图像、横截面扫描电子显微镜图像、光致发光光谱和吸收光谱表明，增加的短路电流密度（J _SC）和增加的填充因子（FF）主要是由于合并的MAPbI _3的形成谷物。此外，封装光伏电池的开路电压 (V OC ) 从 1.01 V 大幅增加到 1.15 V，从而在 30 天后将功率转换效率从 17.89% 提高到 19.55%，这可以解释为由于_增加MAPbI ₃结晶薄膜的载流子密度。值得注意的是，在旋涂过程中使用优化的干燥时间会导致合并的 MAPbI _{3晶粒的形成，同时保持 MAPbI 3} /P3CT-Na 界面处的接触质量，从而提高器件性能和所得产品的使用寿命钙钛矿光伏电池。